A reference question

Finally, a question with substance, not for the location of the bathroom or for a paper clip or a telephone number.

A student needing to write a comparison between CS Lewis's The lion, the witch and the wardrobe and L. Frank Baum's The Wizard of Oz. I directed him to the volumes Twentieth Century Literary Criticism and of Contemporary Literary Criticism. I also showed him how to search for the topics in the OPAC:
Baum, L. Frank (Lyman Frank), 1856-1919 -- Criticism and interpretation. : Moore, Raylyn.
Lewis, C. S. (Clive Staples), 1898-1963 -- Criticism and interpretation. (4 entries; 1 by Harold Bloom, whom I praised and recommended.)
The land of Narnia : Brian Sibley explores the world of C.S. Lewis A children's book, a type that can often be helpful even for adults.